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xtensa: don't use linux IRQ #0
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Linux IRQ #0 is reserved for error reporting and may not be used.
Increase NR_IRQS for one additional slot and increase
irq_domain_add_legacy parameter first_irq value to 1, so that linux
IRQ #0 is not associated with hardware IRQ #0 in legacy IRQ domains.
Introduce macro XTENSA_PIC_LINUX_IRQ for static translation of xtensa
PIC hardware IRQ # to linux IRQ #. Use this macro in XTFPGA platform
data definitions.

This fixes inability to use hardware IRQ #0 in configurations that don't
use device tree and allows for non-identity mapping between linux IRQ #
and hardware IRQ #.

Cc: [email protected]
Signed-off-by: Max Filippov <[email protected]>
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jcmvbkbc committed Jun 5, 2017
1 parent 6bf2896 commit e5c8667
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Showing 6 changed files with 13 additions and 15 deletions.
3 changes: 2 additions & 1 deletion arch/xtensa/include/asm/irq.h
Original file line number Diff line number Diff line change
Expand Up @@ -29,7 +29,8 @@ static inline void variant_irq_disable(unsigned int irq) { }
# define PLATFORM_NR_IRQS 0
#endif
#define XTENSA_NR_IRQS XCHAL_NUM_INTERRUPTS
#define NR_IRQS (XTENSA_NR_IRQS + VARIANT_NR_IRQS + PLATFORM_NR_IRQS)
#define NR_IRQS (XTENSA_NR_IRQS + VARIANT_NR_IRQS + PLATFORM_NR_IRQS + 1)
#define XTENSA_PIC_LINUX_IRQ(hwirq) ((hwirq) + 1)

#if VARIANT_NR_IRQS == 0
static inline void variant_init_irq(void) { }
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5 changes: 0 additions & 5 deletions arch/xtensa/kernel/irq.c
Original file line number Diff line number Diff line change
Expand Up @@ -34,11 +34,6 @@ asmlinkage void do_IRQ(int hwirq, struct pt_regs *regs)
{
int irq = irq_find_mapping(NULL, hwirq);

if (hwirq >= NR_IRQS) {
printk(KERN_EMERG "%s: cannot handle IRQ %d\n",
__func__, hwirq);
}

#ifdef CONFIG_DEBUG_STACKOVERFLOW
/* Debugging check for stack overflow: is there less than 1KB free? */
{
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6 changes: 4 additions & 2 deletions arch/xtensa/platforms/xtfpga/include/platform/hardware.h
Original file line number Diff line number Diff line change
Expand Up @@ -24,16 +24,18 @@

/* Interrupt configuration. */

#define PLATFORM_NR_IRQS 10
#define PLATFORM_NR_IRQS 0

/* Default assignment of LX60 devices to external interrupts. */

#ifdef CONFIG_XTENSA_MX
#define DUART16552_INTNUM XCHAL_EXTINT3_NUM
#define OETH_IRQ XCHAL_EXTINT4_NUM
#define C67X00_IRQ XCHAL_EXTINT8_NUM
#else
#define DUART16552_INTNUM XCHAL_EXTINT0_NUM
#define OETH_IRQ XCHAL_EXTINT1_NUM
#define C67X00_IRQ XCHAL_EXTINT5_NUM
#endif

/*
Expand Down Expand Up @@ -63,5 +65,5 @@

#define C67X00_PADDR (XCHAL_KIO_PADDR + 0x0D0D0000)
#define C67X00_SIZE 0x10
#define C67X00_IRQ 5

#endif /* __XTENSA_XTAVNET_HARDWARE_H */
10 changes: 5 additions & 5 deletions arch/xtensa/platforms/xtfpga/setup.c
Original file line number Diff line number Diff line change
Expand Up @@ -175,8 +175,8 @@ static struct resource ethoc_res[] = {
.flags = IORESOURCE_MEM,
},
[2] = { /* IRQ number */
.start = OETH_IRQ,
.end = OETH_IRQ,
.start = XTENSA_PIC_LINUX_IRQ(OETH_IRQ),
.end = XTENSA_PIC_LINUX_IRQ(OETH_IRQ),
.flags = IORESOURCE_IRQ,
},
};
Expand Down Expand Up @@ -213,8 +213,8 @@ static struct resource c67x00_res[] = {
.flags = IORESOURCE_MEM,
},
[1] = { /* IRQ number */
.start = C67X00_IRQ,
.end = C67X00_IRQ,
.start = XTENSA_PIC_LINUX_IRQ(C67X00_IRQ),
.end = XTENSA_PIC_LINUX_IRQ(C67X00_IRQ),
.flags = IORESOURCE_IRQ,
},
};
Expand Down Expand Up @@ -247,7 +247,7 @@ static struct resource serial_resource = {
static struct plat_serial8250_port serial_platform_data[] = {
[0] = {
.mapbase = DUART16552_PADDR,
.irq = DUART16552_INTNUM,
.irq = XTENSA_PIC_LINUX_IRQ(DUART16552_INTNUM),
.flags = UPF_BOOT_AUTOCONF | UPF_SKIP_TEST |
UPF_IOREMAP,
.iotype = XCHAL_HAVE_BE ? UPIO_MEM32BE : UPIO_MEM32,
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2 changes: 1 addition & 1 deletion drivers/irqchip/irq-xtensa-mx.c
Original file line number Diff line number Diff line change
Expand Up @@ -142,7 +142,7 @@ static struct irq_chip xtensa_mx_irq_chip = {
int __init xtensa_mx_init_legacy(struct device_node *interrupt_parent)
{
struct irq_domain *root_domain =
irq_domain_add_legacy(NULL, NR_IRQS, 0, 0,
irq_domain_add_legacy(NULL, NR_IRQS - 1, 1, 0,
&xtensa_mx_irq_domain_ops,
&xtensa_mx_irq_chip);
irq_set_default_host(root_domain);
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2 changes: 1 addition & 1 deletion drivers/irqchip/irq-xtensa-pic.c
Original file line number Diff line number Diff line change
Expand Up @@ -89,7 +89,7 @@ static struct irq_chip xtensa_irq_chip = {
int __init xtensa_pic_init_legacy(struct device_node *interrupt_parent)
{
struct irq_domain *root_domain =
irq_domain_add_legacy(NULL, NR_IRQS, 0, 0,
irq_domain_add_legacy(NULL, NR_IRQS - 1, 1, 0,
&xtensa_irq_domain_ops, &xtensa_irq_chip);
irq_set_default_host(root_domain);
return 0;
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